preprocessor: Support #warning for standard C2x

ISO C2x standardizes the existing #warning extension.  Arrange
accordingly for it not to be diagnosed with -std=c2x -pedantic, but to
be diagnosed with -Wc11-c2x-compat.

Bootstrapped with no regressions for x86_64-pc-linux-gnu.

gcc/testsuite/
	* gcc.dg/cpp/c11-warning-1.c, gcc.dg/cpp/c11-warning-2.c,
	gcc.dg/cpp/c11-warning-3.c, gcc.dg/cpp/c11-warning-4.c,
	gcc.dg/cpp/c2x-warning-1.c, gcc.dg/cpp/c2x-warning-2.c,
	gcc.dg/cpp/gnu11-warning-1.c, gcc.dg/cpp/gnu11-warning-2.c,
	gcc.dg/cpp/gnu11-warning-3.c, gcc.dg/cpp/gnu11-warning-4.c,
	gcc.dg/cpp/gnu2x-warning-1.c, gcc.dg/cpp/gnu2x-warning-2.c: New
	tests.

libcpp/
	* include/cpplib.h (struct cpp_options): Add warning_directive.
	* init.cc (struct lang_flags, lang_defaults): Add
	warning_directive.
	* directives.cc (DIRECTIVE_TABLE): Mark #warning as STDC2X not
	EXTENSION.
	(directive_diagnostics): Diagnose #warning with -Wc11-c2x-compat,
	or with -pedantic for a standard not supporting #warning.

diff --git a/gcc/testsuite/gcc.dg/cpp/c11-warning-1.c b/gcc/testsuite/gcc.dg/cpp/c11-warning-1.c
new file mode 100644 (file)
index 0000000..45d1ff8
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/cpp/c11-warning-1.c
@@ -0,0 +1,6 @@
+/* Test #warning not in C11.  */
+/* { dg-do preprocess } */
+/* { dg-options "-std=c11 -pedantic-errors" } */
+
+#warning example text /* { dg-warning "example text" } */
+/* { dg-error "#warning before C2X is a GCC extension" "pedantic" { target *-*-* } .-1 } */

diff --git a/gcc/testsuite/gcc.dg/cpp/c11-warning-2.c b/gcc/testsuite/gcc.dg/cpp/c11-warning-2.c
new file mode 100644 (file)
index 0000000..ba385bf
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/cpp/c11-warning-2.c
@@ -0,0 +1,6 @@
+/* Test #warning not in C11.  */
+/* { dg-do preprocess } */
+/* { dg-options "-std=c11 -pedantic" } */
+
+#warning example text /* { dg-warning "example text" } */
+/* { dg-warning "#warning before C2X is a GCC extension" "pedantic" { target *-*-* } .-1 } */

diff --git a/gcc/testsuite/gcc.dg/cpp/c11-warning-3.c b/gcc/testsuite/gcc.dg/cpp/c11-warning-3.c
new file mode 100644 (file)
index 0000000..8d74fcd
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/cpp/c11-warning-3.c
@@ -0,0 +1,6 @@
+/* Test #warning not in C11.  */
+/* { dg-do preprocess } */
+/* { dg-options "-std=c11 -Wc11-c2x-compat" } */
+
+#warning example text /* { dg-warning "example text" } */
+/* { dg-warning "#warning before C2X is a GCC extension" "compat" { target *-*-* } .-1 } */

diff --git a/gcc/testsuite/gcc.dg/cpp/c11-warning-4.c b/gcc/testsuite/gcc.dg/cpp/c11-warning-4.c
new file mode 100644 (file)
index 0000000..0af93f3
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/cpp/c11-warning-4.c
@@ -0,0 +1,6 @@
+/* Test #warning not in C11.  */
+/* { dg-do preprocess } */
+/* { dg-options "-std=c11" } */
+
+#warning example text /* { dg-warning "example text" } */
+/* Not diagnosed by default.  */

diff --git a/gcc/testsuite/gcc.dg/cpp/c2x-warning-1.c b/gcc/testsuite/gcc.dg/cpp/c2x-warning-1.c
new file mode 100644 (file)
index 0000000..696a0cd
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/cpp/c2x-warning-1.c
@@ -0,0 +1,5 @@
+/* Test #warning in C2x.  */
+/* { dg-do preprocess } */
+/* { dg-options "-std=c2x -pedantic-errors" } */
+
+#warning example text /* { dg-warning "example text" } */

diff --git a/gcc/testsuite/gcc.dg/cpp/c2x-warning-2.c b/gcc/testsuite/gcc.dg/cpp/c2x-warning-2.c
new file mode 100644 (file)
index 0000000..3042e7a
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/cpp/c2x-warning-2.c
@@ -0,0 +1,6 @@
+/* Test #warning in C2x: -Wc11-c2x-comapt.  */
+/* { dg-do preprocess } */
+/* { dg-options "-std=c2x -pedantic-errors -Wc11-c2x-compat" } */
+
+#warning example text /* { dg-warning "example text" } */
+/* { dg-warning "#warning before C2X is a GCC extension" "compat" { target *-*-* } .-1 } */

diff --git a/gcc/testsuite/gcc.dg/cpp/gnu11-warning-1.c b/gcc/testsuite/gcc.dg/cpp/gnu11-warning-1.c
new file mode 100644 (file)
index 0000000..7dda115
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/cpp/gnu11-warning-1.c
@@ -0,0 +1,6 @@
+/* Test #warning not in C11.  */
+/* { dg-do preprocess } */
+/* { dg-options "-std=gnu11 -pedantic-errors" } */
+
+#warning example text /* { dg-warning "example text" } */
+/* { dg-error "#warning before C2X is a GCC extension" "pedantic" { target *-*-* } .-1 } */

diff --git a/gcc/testsuite/gcc.dg/cpp/gnu11-warning-2.c b/gcc/testsuite/gcc.dg/cpp/gnu11-warning-2.c
new file mode 100644 (file)
index 0000000..af2cc34
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/cpp/gnu11-warning-2.c
@@ -0,0 +1,6 @@
+/* Test #warning not in C11.  */
+/* { dg-do preprocess } */
+/* { dg-options "-std=gnu11 -pedantic" } */
+
+#warning example text /* { dg-warning "example text" } */
+/* { dg-warning "#warning before C2X is a GCC extension" "pedantic" { target *-*-* } .-1 } */

diff --git a/gcc/testsuite/gcc.dg/cpp/gnu11-warning-3.c b/gcc/testsuite/gcc.dg/cpp/gnu11-warning-3.c
new file mode 100644 (file)
index 0000000..22b7b50
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/cpp/gnu11-warning-3.c
@@ -0,0 +1,6 @@
+/* Test #warning not in C11.  */
+/* { dg-do preprocess } */
+/* { dg-options "-std=gnu11 -Wc11-c2x-compat" } */
+
+#warning example text /* { dg-warning "example text" } */
+/* { dg-warning "#warning before C2X is a GCC extension" "compat" { target *-*-* } .-1 } */

diff --git a/gcc/testsuite/gcc.dg/cpp/gnu11-warning-4.c b/gcc/testsuite/gcc.dg/cpp/gnu11-warning-4.c
new file mode 100644 (file)
index 0000000..fd8ecfb
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/cpp/gnu11-warning-4.c
@@ -0,0 +1,6 @@
+/* Test #warning not in C11.  */
+/* { dg-do preprocess } */
+/* { dg-options "-std=gnu11" } */
+
+#warning example text /* { dg-warning "example text" } */
+/* Not diagnosed by default.  */

diff --git a/gcc/testsuite/gcc.dg/cpp/gnu2x-warning-1.c b/gcc/testsuite/gcc.dg/cpp/gnu2x-warning-1.c
new file mode 100644 (file)
index 0000000..c8e5290
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/cpp/gnu2x-warning-1.c
@@ -0,0 +1,5 @@
+/* Test #warning in C2x.  */
+/* { dg-do preprocess } */
+/* { dg-options "-std=gnu2x -pedantic-errors" } */
+
+#warning example text /* { dg-warning "example text" } */

diff --git a/gcc/testsuite/gcc.dg/cpp/gnu2x-warning-2.c b/gcc/testsuite/gcc.dg/cpp/gnu2x-warning-2.c
new file mode 100644 (file)
index 0000000..3aef4b3
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/cpp/gnu2x-warning-2.c
@@ -0,0 +1,6 @@
+/* Test #warning in C2x: -Wc11-c2x-comapt.  */
+/* { dg-do preprocess } */
+/* { dg-options "-std=gnu2x -pedantic-errors -Wc11-c2x-compat" } */
+
+#warning example text /* { dg-warning "example text" } */
+/* { dg-warning "#warning before C2X is a GCC extension" "compat" { target *-*-* } .-1 } */

diff --git a/libcpp/directives.cc b/libcpp/directives.cc
index 4104d51..802bd8c 100644 (file)
--- a/libcpp/directives.cc
+++ b/libcpp/directives.cc
@@ -158,7 +158,7 @@ static void cpp_pop_definition (cpp_reader *, struct def_pragma_macro *);
   D(elifndef,  T_ELIFNDEF,     STDC2X,    COND | ELIFDEF)              \
   D(error,     T_ERROR,        STDC89,    0)                           \
   D(pragma,    T_PRAGMA,       STDC89,    IN_I)                        \
-  D(warning,   T_WARNING,      EXTENSION, 0)                           \
+  D(warning,   T_WARNING,      STDC2X,    0)                           \
   D(include_next, T_INCLUDE_NEXT, EXTENSION, INCL | EXPAND)            \
   D(ident,     T_IDENT,        EXTENSION, IN_I)                        \
   D(import,    T_IMPORT,       EXTENSION, INCL | EXPAND)  /* ObjC */   \
@@ -385,6 +385,15 @@ directive_diagnostics (cpp_reader *pfile, const directive *dir, int indented)
          && !(dir == &dtable[T_IMPORT] && CPP_OPTION (pfile, objc))
          && CPP_PEDANTIC (pfile))
        cpp_error (pfile, CPP_DL_PEDWARN, "#%s is a GCC extension", dir->name);
+      else if (dir == &dtable[T_WARNING])
+       {
+         if (CPP_PEDANTIC (pfile) && !CPP_OPTION (pfile, warning_directive))
+           cpp_error (pfile, CPP_DL_PEDWARN,
+                      "#%s before C2X is a GCC extension", dir->name);
+         else if (CPP_OPTION (pfile, cpp_warn_c11_c2x_compat) > 0)
+           cpp_warning (pfile, CPP_W_C11_C2X_COMPAT,
+                        "#%s before C2X is a GCC extension", dir->name);
+       }
       else if (((dir->flags & DEPRECATED) != 0
                || (dir == &dtable[T_IMPORT] && !CPP_OPTION (pfile, objc)))
               && CPP_OPTION (pfile, cpp_warn_deprecated))

diff --git a/libcpp/include/cpplib.h b/libcpp/include/cpplib.h
index 26e2b4c..58ed51d 100644 (file)
--- a/libcpp/include/cpplib.h
+++ b/libcpp/include/cpplib.h
@@ -513,6 +513,9 @@ struct cpp_options
   /* Nonzero for the '#elifdef' and '#elifndef' directives.  */
   unsigned char elifdef;
 
+  /* Nonzero for the '#warning' directive.  */
+  unsigned char warning_directive;
+
   /* Nonzero means tokenize C++20 module directives.  */
   unsigned char module_directives;
 

diff --git a/libcpp/init.cc b/libcpp/init.cc
index 59641a7..8d99bdb 100644 (file)
--- a/libcpp/init.cc
+++ b/libcpp/init.cc
@@ -96,34 +96,35 @@ struct lang_flags
   char dfp_constants;
   char size_t_literals;
   char elifdef;
+  char warning_directive;
 };
 
 static const struct lang_flags lang_defaults[] =
-{ /*              c99 c++ xnum xid c11 std digr ulit rlit udlit bincst digsep trig u8chlit vaopt scope dfp szlit elifdef */
-  /* GNUC89   */  { 0,  0,  1,  0,  0,  0,  1,   0,   0,   0,    0,     0,     0,   0,      1,   1,     0,   0,   0 },
-  /* GNUC99   */  { 1,  0,  1,  1,  0,  0,  1,   1,   1,   0,    0,     0,     0,   0,      1,   1,     0,   0,   0 },
-  /* GNUC11   */  { 1,  0,  1,  1,  1,  0,  1,   1,   1,   0,    0,     0,     0,   0,      1,   1,     0,   0,   0 },
-  /* GNUC17   */  { 1,  0,  1,  1,  1,  0,  1,   1,   1,   0,    0,     0,     0,   0,      1,   1,     0,   0,   0 },
-  /* GNUC2X   */  { 1,  0,  1,  1,  1,  0,  1,   1,   1,   0,    1,     1,     0,   1,      1,   1,     1,   0,   1 },
-  /* STDC89   */  { 0,  0,  0,  0,  0,  1,  0,   0,   0,   0,    0,     0,     1,   0,      0,   0,     0,   0,   0 },
-  /* STDC94   */  { 0,  0,  0,  0,  0,  1,  1,   0,   0,   0,    0,     0,     1,   0,      0,   0,     0,   0,   0 },
-  /* STDC99   */  { 1,  0,  1,  1,  0,  1,  1,   0,   0,   0,    0,     0,     1,   0,      0,   0,     0,   0,   0 },
-  /* STDC11   */  { 1,  0,  1,  1,  1,  1,  1,   1,   0,   0,    0,     0,     1,   0,      0,   0,     0,   0,   0 },
-  /* STDC17   */  { 1,  0,  1,  1,  1,  1,  1,   1,   0,   0,    0,     0,     1,   0,      0,   0,     0,   0,   0 },
-  /* STDC2X   */  { 1,  0,  1,  1,  1,  1,  1,   1,   0,   0,    1,     1,     1,   1,      0,   1,     1,   0,   1 },
-  /* GNUCXX   */  { 0,  1,  1,  1,  0,  0,  1,   0,   0,   0,    0,     0,     0,   0,      1,   1,     0,   0,   0 },
-  /* CXX98    */  { 0,  1,  0,  1,  0,  1,  1,   0,   0,   0,    0,     0,     1,   0,      0,   1,     0,   0,   0 },
-  /* GNUCXX11 */  { 1,  1,  1,  1,  1,  0,  1,   1,   1,   1,    0,     0,     0,   0,      1,   1,     0,   0,   0 },
-  /* CXX11    */  { 1,  1,  0,  1,  1,  1,  1,   1,   1,   1,    0,     0,     1,   0,      0,   1,     0,   0,   0 },
-  /* GNUCXX14 */  { 1,  1,  1,  1,  1,  0,  1,   1,   1,   1,    1,     1,     0,   0,      1,   1,     0,   0,   0 },
-  /* CXX14    */  { 1,  1,  0,  1,  1,  1,  1,   1,   1,   1,    1,     1,     1,   0,      0,   1,     0,   0,   0 },
-  /* GNUCXX17 */  { 1,  1,  1,  1,  1,  0,  1,   1,   1,   1,    1,     1,     0,   1,      1,   1,     0,   0,   0 },
-  /* CXX17    */  { 1,  1,  1,  1,  1,  1,  1,   1,   1,   1,    1,     1,     0,   1,      0,   1,     0,   0,   0 },
-  /* GNUCXX20 */  { 1,  1,  1,  1,  1,  0,  1,   1,   1,   1,    1,     1,     0,   1,      1,   1,     0,   0,   0 },
-  /* CXX20    */  { 1,  1,  1,  1,  1,  1,  1,   1,   1,   1,    1,     1,     0,   1,      1,   1,     0,   0,   0 },
-  /* GNUCXX23 */  { 1,  1,  1,  1,  1,  0,  1,   1,   1,   1,    1,     1,     0,   1,      1,   1,     0,   1,   1 },
-  /* CXX23    */  { 1,  1,  1,  1,  1,  1,  1,   1,   1,   1,    1,     1,     0,   1,      1,   1,     0,   1,   1 },
-  /* ASM      */  { 0,  0,  1,  0,  0,  0,  0,   0,   0,   0,    0,     0,     0,   0,      0,   0,     0,   0,   0 }
+{ /*              c99 c++ xnum xid c11 std digr ulit rlit udlit bincst digsep trig u8chlit vaopt scope dfp szlit elifdef warndir */
+  /* GNUC89   */  { 0,  0,  1,  0,  0,  0,  1,   0,   0,   0,    0,     0,     0,   0,      1,   1,     0,   0,   0,      0 },
+  /* GNUC99   */  { 1,  0,  1,  1,  0,  0,  1,   1,   1,   0,    0,     0,     0,   0,      1,   1,     0,   0,   0,      0 },
+  /* GNUC11   */  { 1,  0,  1,  1,  1,  0,  1,   1,   1,   0,    0,     0,     0,   0,      1,   1,     0,   0,   0,      0 },
+  /* GNUC17   */  { 1,  0,  1,  1,  1,  0,  1,   1,   1,   0,    0,     0,     0,   0,      1,   1,     0,   0,   0,      0 },
+  /* GNUC2X   */  { 1,  0,  1,  1,  1,  0,  1,   1,   1,   0,    1,     1,     0,   1,      1,   1,     1,   0,   1,      1 },
+  /* STDC89   */  { 0,  0,  0,  0,  0,  1,  0,   0,   0,   0,    0,     0,     1,   0,      0,   0,     0,   0,   0,      0 },
+  /* STDC94   */  { 0,  0,  0,  0,  0,  1,  1,   0,   0,   0,    0,     0,     1,   0,      0,   0,     0,   0,   0,      0 },
+  /* STDC99   */  { 1,  0,  1,  1,  0,  1,  1,   0,   0,   0,    0,     0,     1,   0,      0,   0,     0,   0,   0,      0 },
+  /* STDC11   */  { 1,  0,  1,  1,  1,  1,  1,   1,   0,   0,    0,     0,     1,   0,      0,   0,     0,   0,   0,      0 },
+  /* STDC17   */  { 1,  0,  1,  1,  1,  1,  1,   1,   0,   0,    0,     0,     1,   0,      0,   0,     0,   0,   0,      0 },
+  /* STDC2X   */  { 1,  0,  1,  1,  1,  1,  1,   1,   0,   0,    1,     1,     1,   1,      0,   1,     1,   0,   1,      1 },
+  /* GNUCXX   */  { 0,  1,  1,  1,  0,  0,  1,   0,   0,   0,    0,     0,     0,   0,      1,   1,     0,   0,   0,      0 },
+  /* CXX98    */  { 0,  1,  0,  1,  0,  1,  1,   0,   0,   0,    0,     0,     1,   0,      0,   1,     0,   0,   0,      0 },
+  /* GNUCXX11 */  { 1,  1,  1,  1,  1,  0,  1,   1,   1,   1,    0,     0,     0,   0,      1,   1,     0,   0,   0,      0 },
+  /* CXX11    */  { 1,  1,  0,  1,  1,  1,  1,   1,   1,   1,    0,     0,     1,   0,      0,   1,     0,   0,   0,      0 },
+  /* GNUCXX14 */  { 1,  1,  1,  1,  1,  0,  1,   1,   1,   1,    1,     1,     0,   0,      1,   1,     0,   0,   0,      0 },
+  /* CXX14    */  { 1,  1,  0,  1,  1,  1,  1,   1,   1,   1,    1,     1,     1,   0,      0,   1,     0,   0,   0,      0 },
+  /* GNUCXX17 */  { 1,  1,  1,  1,  1,  0,  1,   1,   1,   1,    1,     1,     0,   1,      1,   1,     0,   0,   0,      0 },
+  /* CXX17    */  { 1,  1,  1,  1,  1,  1,  1,   1,   1,   1,    1,     1,     0,   1,      0,   1,     0,   0,   0,      0 },
+  /* GNUCXX20 */  { 1,  1,  1,  1,  1,  0,  1,   1,   1,   1,    1,     1,     0,   1,      1,   1,     0,   0,   0,      0 },
+  /* CXX20    */  { 1,  1,  1,  1,  1,  1,  1,   1,   1,   1,    1,     1,     0,   1,      1,   1,     0,   0,   0,      0 },
+  /* GNUCXX23 */  { 1,  1,  1,  1,  1,  0,  1,   1,   1,   1,    1,     1,     0,   1,      1,   1,     0,   1,   1,      0 },
+  /* CXX23    */  { 1,  1,  1,  1,  1,  1,  1,   1,   1,   1,    1,     1,     0,   1,      1,   1,     0,   1,   1,      0 },
+  /* ASM      */  { 0,  0,  1,  0,  0,  0,  0,   0,   0,   0,    0,     0,     0,   0,      0,   0,     0,   0,   0,      0 }
 };
 
 /* Sets internal flags correctly for a given language.  */
@@ -153,6 +154,7 @@ cpp_set_lang (cpp_reader *pfile, enum c_lang lang)
   CPP_OPTION (pfile, dfp_constants)             = l->dfp_constants;
   CPP_OPTION (pfile, size_t_literals)           = l->size_t_literals;
   CPP_OPTION (pfile, elifdef)                   = l->elifdef;
+  CPP_OPTION (pfile, warning_directive)                 = l->warning_directive;
 }
 
 /* Initialize library global state.  */